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内部缺陷对高压直流电缆电场分布影响的有限元分析

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南方电网技术 2015年第10期9卷 83-91页

作者：何淼 George Chen paul l.lewin 南安普顿大学

高压直流电缆实际运行过程中可能会有缺陷出现,使得电缆内部电场分布发生畸变,加速绝缘材料的老化。运用有限元分析的方法,对直流电缆电场分布进行了二维和三维建模和仿真分析,研究了不同电缆绝缘层温差、缺陷位置及尺寸情况下电缆中单... 详细信息

高压直流电缆实际运行过程中可能会有缺陷出现,使得电缆内部电场分布发生畸变,加速绝缘材料的老化。运用有限元分析的方法,对直流电缆电场分布进行了二维和三维建模和仿真分析,研究了不同电缆绝缘层温差、缺陷位置及尺寸情况下电缆中单个球形缺陷对周围绝缘材料的影响,得到了较为通用的直流电缆缺陷对电场畸变的计算公式。研究发现三维仿真更加适合对缺陷进行研究,稳态下缺陷对电场的加强决定于材料的电导率。

关键词：高压直流电缆稳态内部缺陷有限元分析电场加强电场反转电导率

Integration of multiple flexible electrodes for realtime detection of barrier formation with spatial resolution in a gut-on-chip system

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Microsystems & Nanoengineering 2024年第1期10卷 105-114页

作者： Mara lucchetti Gabriel Werr Sofia Johansson laurent Barbe léa Grandmougin paul Wilmes Maria Tenje luxembourg Centre for Systems Biomedicine(lCSB) University of LuxembourgEsch-sur-Alzette L-4362Luxembourg Division of Biomedical Engineering Department of Materials Science and EngineeringScience for Life LaboratoryUppsala University75121 UppsalaSweden Department of life Sciences and Medicine Faculty of ScienceTechnology and MedicineUniversity of LuxembourgEsch-sur-Alzette L-4362Luxembourg

In healthy individuals,the intestinal epithelium forms a tight barrier to prevent gut bacteria from reaching blood *** study the effect of probiotics,dietary compounds and drugs on gut barrier formation and disruption,human gut epithelial and bacterial cells can be cocultured in an in vitro model called the human microbial crosstalk(HuMiX)gut-on-a-chip ***,we present the design,fabrication and integration of thin-film electrodes into the HuMiX platform to measure transepithelial electrical resistance(TEER)as a direct readout on barrier tightness in *** various aspects of the HuMiX platform have already been set in their design,such as multiple compressible layers,uneven surfaces and nontransparent materials,a novel fabrication method was developed whereby thin-film metal electrodes were first deposited on flexible substrates and sequentially integrated with the HuMiX system via a transfer-tape ***,to measure localized TEER along the cell culture chamber,we integrated multiple electrodes that were connected to an impedance analyzer via a *** further developed a dynamic normalization method because the active measurement area depends on the measured TEER *** fabrication process and system setup can be applicable to other barrier-on-chip *** a proof-of-concept,we measured the barrier formation of a cancerous Caco-2 cell line in real-time,which was mapped at four spatially separated positions along the HuMiX culture area.

关键词： barrier system multiple

Quantifying source-sink relationships in leaf-color modified rice genotypes during grain filling

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Journal of Integrative Agriculture 2024年第9期23卷 2923-2940页

作者： Zhenxiang Zhou paul CStruik Junfei Gu Peter E.l.van der Putten Zhiqin Wang Jianchang Yang Xinyou Yin Centre for Crop Systems Analysis Department of Plant SciencesWageningen University&ResearchWageningen 6700 AKThe Netherlands College of Agriculture Yangzhou UniversityYangzhou 225009China

leaf-color modification can affect canopy photosynthesis,with potential effects on rice yield and yield *** source-sink relationships through crop management is often used to improve crop *** study investigated whether and how modifying leaf color alters source-sink relationships and whether current crop cultivation practices remain applicable for leaf-color modified *** collected data of total biomass and nitrogen(N)accumulation in rice genotypes of four genetic backgrounds and their leaf-color modified variants(greener or yellower)were analyzed,using a recently established modelling method to quantify the source-sink(im)balance during grain *** all leaf-color variants,only one yellower-leaf variant showed a higher source capacity than its normal *** was associated with greater post-flowering N-uptake that prolonged the functional leaf-N duration,and this greater post-flowering N-uptake was possible because of reduced pre-flowering N-uptake.A density experiment showed that current management practices(insufficient planting density accompanied by abundant N application)are unsuitable for the yellower-leaf genotype,ultimately limiting its yield ***-color modification affects source-sink relationships by regulating the N trade-off between pre-and post-flowering uptake,as well as N translocation between source and sink *** best exploit leaf-color modification for improving crop productivity,adjustments of crop management practices are required.

关键词： source-sink relationship biomass nitrogen Oryza sativa leaf-color modification

Surface engineering with ionic polymers on membranes for boron removal

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 61-69页

作者： Xiting Zhang Chenyi Fang J paul Chen Sui Zhang Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117576Singapore Department of Civil and Environmental Engineering National University of SingaporeSingapore 119260Singapore College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Removal of boric acid from seawater and wastewater using reverse osmosis membrane technologies is imperative and yet remains inadequately addressed by current commercial *** research efforts performed post-modification of reverse osmosis membranes to enhance boron rejection,which is usually accompanied by substantial sacrifice in water *** study delves into the surface engineering of low-pressure reverse osmosis membranes,aiming to elevate boron removal efficiency while maintaining optimal salt rejection and water *** were modified by the self-polymerization and co-deposition of dopamine and polystyrene sulfonate at varying ratios and *** surfaces became smoother and more hydrophilic after *** optimum membrane exhibited a water permeability of 9.2±0.1 l·m^(-2)·h^(-1)·bar^(-1),NaCl rejection of 95.8%±0.3%,and boron rejection of 49.7%±0.1% and 99.6%±0.3% at neutral and alkaline pH,*** water permeability is reduced by less than 15%,while the boron rejection is 3.7 times higher compared to the blank *** research provides a promising avenue for enhancing boron removal in reverse osmosis membranes and addressing water quality concerns in the desalination process.

关键词： membrane low-pressure reverse osmosis boron surface engineering

Post-fire recovery of Puya raimondii, vegetation and birds in the puna of Huascarán National Park, Perú

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Journal of Mountain Science 2024年第1期21卷 20-32页

作者： Mery l.SUNI Giovana P.VADIllO César ARANA Enoc JARA-PENA letty SAlINAS M.Estela PONCE paul M.RAMSAY Plant Physiology laboratory Faculty of Biological SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Natural History Museum Universidad Nacional Mayor de San MarcosLima 15072Peru Applied Phytology laboratory Faculty of Biological SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Department of Statistics Faculty of Mathematical SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Department of Chemical and Biological Sciences Universidad de las Américas PueblaSan Andrés Cholula CP Cholula CP 72810Mexico

A large fire of 233 ha in Huascarán National Park in Peru provided an opportunity to compare plant and bird responses in burned and nearby unburned zones of the puna. Heights and live diameters of flagship Puya raimondii rosettes(assigned to four broad developmental phases), plant communities(66 species in 24 families and nine growth forms) and bird communities(77 species in six trophic guilds) were monitored after the fire. Although no mortality was observed, Puya raimondii plants were affected by the fire, losing approximately 60% of their photosynthetic area across all developmental phases, but recovered quickly during the first two years after fire. The comparison of Puya rosette recovery after fire was complicated by the changes in live rosette diameter for unburned plants, which showed plasticity of photosynthetic area linked to seasonal and annual fluctuations in precipitation in this relatively dry environment(decreased by 26% for mature adult plants over the study period). Fire caused an immediate change in the density, biomass and composition of vegetation. Although the species present remained similar, their abundances changed significantly immediately after the fire, with notable reductions in dominant tussock grasses. This provided opportunities for other plants, resulting in higher postfire diversity of plant species, genera, families and growth forms. In turn, the changes in vegetation after fire affected the composition of birds according to their trophic guild. Granivores largely disappeared,generalists were mostly unaffected, and other guilds showed a more complex response. As the vegetation recovered, most displaced birds returned within approximately one year.

关键词： Burning Plant biomass Trophic guilds Andes Giant rosette plants

The penetration depth of atomic radicals in tubes with catalytic surface properties

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Plasma Science and Technology 2024年第7期26卷 157-164页

作者： Domen paul Miran MOZETIC Rok ZAPlOTNIK Alenka VESEl Gregor PRIMC Denis DONlAGIC Jozef Stefan Institute Jamova Cesta 39Ljubljana 1000Slovenia Jozef Stefan International Postgraduate School Jamova Cesta 39Ljubljana 1000Slovenia Faculty of Electrical Engineering and Computer Science University of MariborKoroska Cesta 46Maribor 2000Slovenia

Catalysis of molecular radicals is often performed in interesting experimental *** possible configuration is tubular *** radicals are introduced into the tubes on one side,and stable molecules are exhausted on the other *** penetration depth of radicals depends on numerous parameters,so it is not always feasible to calculate *** article presents systematic measurements of the penetration depth of oxygen atoms along tubes made from nickel,cobalt,and *** source of O atoms was a surfatron-type microwave *** initial density of O atoms depended on the gas flow and was 0.7×10^(21)m^(-3),2.4×10^(21)m^(-3),and 4.2×10^(21)m^(-3)at the flow rates of 50,300,and 600 sccm,and pressures of 10,35,and 60 Pa,*** gas temperature remained at room temperature throughout the *** dissociation fraction decreased exponentially along the length of the tubes in all *** penetration depths for well-oxidized nickel were 1.2,1.7,and 2.4 cm,*** cobalt,they were slightly lower at 1.0,1.3,and 1.6 cm,respectively,while for copper,they were 1.1,1.3,and 1.7 cm,*** results were explained by gas dynamics and heterogeneous surface *** data are useful in any attempt to estimate the loss of molecular fragments along tubes,which serve as catalysts for the association of various radicals to stable molecules.

关键词： oxygen plasma penetration depth catalysis heterogeneous surface recombination atom loss

New insights into protein–polysaccharide complex coacervation:Dynamics,molecular parameters,and applications

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Aggregate 2024年第1期5卷 148-166页

作者： Jiabao Zheng paul Van der Meeren Weizheng Sun School of Food Science and Engineering South China University of TechnologyGuangzhouChina Department of Green Chemistry and Technology Faculty of Bioscience EngineeringGhent UniversityGhentBelgium Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health(111 Center) GuangzhouChina

For more than a decade,the discovery of liquid–liquid phase separation within living organisms has prompted colloid scientists to understand the connection between coacervate functionality,phase behavior,and dynamics at a multidisciplinary *** the protein–polysaccharide was the first system in which the coacervation phenomenon was discovered and is widely used in food systems,the phase state and relaxation dynamics of protein–polysaccharide complex coacervates(PPCC)have rarely been discussed ***,this review aims to unravel the relationship between PPCC dynamics,thermodynamics,molecular architecture,applications,and phase states in past *** ahead,solving the way molecular architecture spreads to macro-functionality,that is,establishing the relationship between molecular architecture–dynamics–application,will catalyze novel advancements in PPCC research within the field of foods and biomaterials.

关键词： dynamics encapsulation liquid coacervate protein-polysaccharide complex coacervation solid precipitate

Hypoxic and temporal variation in the endocrine disrupting toxicity of perfluorobutanesulfonate in marine medaka(Oryzias melastigma)

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Journal of Environmental Sciences 2024年第2期136卷 279-291页

作者： Baili Sun Jing li Yachen Bai Xiangzhen Zhou paul K.S.lam lianguo Chen State Key laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of Chinese Academy of Sciences Beijing 100049China Office of the President Hong Kong Metropolitan University30 Good Shepherd StreetKowloonHong Kong SARChina

Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of ***,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity remain largely *** the present study,adult marine medaka were exposed to environmentally realistic concentrations of PFBS(0 and 10μg/l)under normoxia or hypoxia conditions for 7 days,aiming to explore the interactive behavior between PFBS and *** addition,PFBS singular exposure was extended till 21days under normoxia to elucidate the time-course progression in PFBS *** results showed that hypoxia inhibited the growth and caused the suspension of egg spawn regardless of PFBS *** regard to the sex endocrine system,7-day PFBS exposure led to an acute stimulation of transcriptional profiles in females,which,subsequently,recovered after the 21-day *** potency of hypoxia to disturb the sex hormones was much stronger than PFBS.A remarkable increase in estradiol concentration was noted in medaka blood after hypoxia *** in sex endocrinology of coexposed fish were largely determined by hypoxia,which drove the formation of an estrogenic *** further enhanced the endocrine disrupting effects of ***,the hepatic synthesis of vitellogenin and choriogenin,two commonly used sensitive biomarkers of estrogenic activity,failed to initiate in response to the estrogen *** to sex endocrine system,disturbances in thyroidal axis by PFBS or hypoxia were relatively ***,the present findings will advance our toxicological understanding about PFBS pollutant under the interference of hypoxia.

关键词： Perfluorobutanesulfonate(PFBS) Aquatic hypoxia Temporal toxicity Combined exposure Endocrine disruption Marine medaka

Three-stage pyrolysis–steam reforming–water gas shift processing of household,commercial and industrial waste plastics for hydrogen production

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Waste Disposal and Sustainable Energy 2024年第1期6卷 25-37页

作者： Rayed Alshareef Robert Sait-Stewart Mohamad A.Nahil paul T.Williams School of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Five common single plastics and nine different household,commercial and industrial waste plastics were processed using a three-stage(i)pyrolysis,(ii)catalytic steam reforming and(iii)water gas shift reaction system to produce *** of plastics produces a range of different hydrocarbon species which are subsequently catalytically steam reformed to produce H_(2)and CO and then undergo water gas shift reaction to produce further H_(2).The process mimics the commercial process for hydrogen production from natural *** of the single polyalkene plastics(high-density polyethylene(HDPE),low-density polyethylene(lDPE),and polypropylene(PP))produced similar H_(2)yields between 115 mmol and 120 mmol per gram *** though PS produced an aromatic product slate from the pyrolysis stage,further stages of reforming and water gas shift reaction produced a gas yield and composition similar to that of the polyalkene plastics(115 mmol H_(2)per gram plastic).PET gave significantly lower H_(2)yield(41 mmol per gram plastic)due to the formation of mainly CO,CO_(2)and organic acids from the pyrolysis stage which were not conducive to further reforming and water gas shift reaction.A mixture of the single plastics typical of that found in municipal solid waste produced a H_(2)yield of 102 mmol per gram *** the gas yields and composition from the single plastics enabled an estimation of the yields from a simulated waste plastic mixture and a‘real-world’waste plastic mixture to be *** different household,commercial and industrial waste plastic mixtures produced H_(2)yields between 70 mmol and 107 mmol per gram *** H_(2)yield and gas composition from the single waste plastics gave an indication of the type of plastics in the mixed waste plastic samples.

关键词： Waste plastic Hydrogen Catalyst Pyrolysis reforming Water gas shift